1. Which of the following is an example of a positive mutation? 2 points
(A) The disease, cystic fibrosis, is caused by any of over 1300 mutations on a single
gene
O (B) A white bear is produced in the B. C. black bear population
(C) A human carries a mutated gene that makes that individual resistant to HIV
infection
(D) People who carry the sickle cell gene have c-shaped red blood cells that can block
blood flow

1. true.2. true.3. true.4. false.5. true.the concept of darwin's theory of evolution involves the idea that there are limited resources in a given living environment and that the organisms which live within have variations in their genetic make up due to random mating. the ones with beneficial genetic variations can express certain traits which give them an upper hand in surviving and reproducing in the said environment compared to ones who may have a more disadvantageous variation in traits. over time, the organisms with an upper hand will survive and reproduce more frequently and pass on their beneficial genes while the others die. the result is evolution, where we observe (usually, but not always) eventually, phenotypic distinct changes.

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